Li-Po batteries can be highly dangerous, and many people have no idea!
For years, lithium polymer batteries (Li-Pos) have been known to be dangerous and unpredictable. Dropping, denting or crushing can shorten the life of the battery and even cause an internal short — a recipe for fire. There are a myriad of guidelines for storing, charging and transporting them. Even among experienced RC users, they have led to fires.
The #1 tip is to never leave a Li-Po battery unattended during the charging or discharging process.